Yesterday I was able to finish soldering the board. Here you can see it during first test with CM4 connected to power supply:
As can be seen it went well, so I went on. This is how finished board looks like:
Generally, differences between this and previous board are almost unnoticeable and this is how it should be. It was meant to be, let's say, "bugfix" release. Existing problems indeed seems to be fixed now. In the final board however I encountered new issue - Ethernet does not want to negotiate 1 Gbps, what is unfortunate and regression since the first iteration. But I suspect it is build related, as the only modification around Ethernet connector and traces was diameter of shield mounting hole, which I believe did not cause this issue. Anyway I am going to investigate this and hopefully will be able to either fix it, or assemble another board to check if it persists.
For now I can sum up this iteration as (only small - due to Ethernet) success. Next goal is to set up some software in the direction of clustering and eliminating Micro SD card. I am also considering doing some modifications on the board, especially location of LEDs, as these are not exactly convenient for mounting in something like racks, what might be a problem for some people. And of course there is still supply chain problem for which I do not have any workaround, at least for now. I will keep posting updates in case of any news in the project.